code: def test_hrf_norm_and_length(
      hrf_model, tr, expected_integral, expected_length
  ):
      """Test that the hrf models are correctly normalized and \
      have correct lengths."""
      h = hrf_model(tr)
  
      assert_almost_equal(h.sum(), expected_integral)
      assert len(h) == expected_length
  
imports: import warnings
  import numpy
  import pytest
  from numpy.testing import assert_almost_equal, assert_array_almost_equal, assert_array_equal
  from nilearn.glm.first_level.hemodynamic_models import _calculate_tr, _hrf_kernel, _regressor_names, _resample_regressor, _sample_condition, compute_regressor, glover_dispersion_derivative, glover_hrf, glover_time_derivative, orthogonalize, spm_dispersion_derivative, spm_hrf, spm_time_derivative
label_desc: Use image node_id 3 for calling a global function with example usage: test_hrf_norm_and_length(hrf_model, tr, expected_integral, expected_length) without return types